Door control unit

ABSTRACT

A DOOR CONTROL UNIT ADAPTED FOR INSTALLATION IN SHALLOW FLOORS OR FRAMES AND WHEREIN A CARTRIDGE COMPRISING A HYDRAULIC DOOR CHECKING MECHANISM A DRIVEN MEMBER AND A SPRING ACTUATOR MAY BE REMOVED FROM THE HOUSING OF THE DOOR CONTROL UNIT WITHOUT REMOVING THE DOOR FROM THE SPINDLE.

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D. H. ELLIS DOOR CONTROL UNIT Filed Oct. 16, 1969 Illll lFlll [\ul IIIII'ILI l I I l l I l Nov. 9, 1971 2 *1 In as 4,307 Dd viafl. X57513 3M EM rm 9 W Jil a 3 Sheets-Sheet 2 D. H. ELLIS DOOR CONTROL UNIT Nov. 9, 1971 Filed Oct. 16. 1969 Y (ll/07a QNN Nov. 9, 1971 o. H. ELLIS 3,618,160

DOOR CONTROL UNIT Filed Oct. 16, 1969 3 Sheets-Sheet :5

United States Patent 3,618,160 DOOR CONTROL UNIT David H. Ellis, West Chicago, Ill., assignor to Rlxson Inc., Franklin Park, 111. Filed Oct. 16, 1969, Ser. No. 867,031 Int. Cl. EOSf 3/20 U.S. Cl. 16--55 30 Claims ABSTRACT OF THE DISCLOSURE A door control unit adapted for installation in shallow floors or frames and wherein a cartridge comprising a hydraulic door checking mechanism, a driven member and a spring actuator may be removed from the housing of the door control unit without removing the door from the spindle.

BACKGROUND OF THE INVENTION Because buildings are being designed to have thinner floors and shallower door frames, many prior forms of door control units are unsuitable because of their excessive vertical dimension.

Accordingly, it is one of the objects of this invention to provide a doorcontrol unit which is shallow yet durable and which provides reliable door control in both directions of movement of the door with a single cylinder having a double-acting piston.

The maintenance, replacement or repair of door control units frequently is difficult and expensive. In most in stances the door must be removed if the hydraulic door checking mechanism and spring actuator are to be replaced. .Accordingly, it is a further object of the invention to simplify the maintenance, replacement or repair of the door control unit by providing a removable cartridge which carries the hydraulic door checking mechanism, a spring actuator and a driven member which is interconnected with both of the prior two structures, with said cartridge being removable without the necessity of removing the door from the spindle.

It is another object of the invention to provide a simple way to secure the cartridge within the housing of the door control unit.

It is yet another object of the invention to so dispose the operating parts of the cartridge that they require less vertical space, thereby permitting the vertical dimensions of the door control unit to be less than usual. To further render the overall vertical dimensions less than usual I require only a single housing which also serves as a cement case.

It is a further object of the invention to provide a shallow door control unit, as described above, which incorporates a door hold-open mechanism.

It is still a further object of the invention to provide simple means for adjusting the position of the cartridge in the housing either for initial installation or to take up wear.

SUMMARY OF THE INVENTION The door control unit of this invention is designed to fit into a shallow recess provided in either the floor or door frame. All of the operating components of the door control unit are contained in a removable cartridge with the exception of the spindle, which is driven by movement of the door, and the gear segment which is associated with the spindle. The spindle is mounted in a thinwall casing that serves as the housing for the door control unit.

The frame of the cartridge consists of two spaced plates, or arms, interconnected by a bight portion to pro vide a U-shapecl cross section. At one end of the cartridge a hydraulic door check mechanism is mounted between the spaced plates near the bight portion of the frame such that a part of the hydraulic door check mechanism protrudes above and below, respectively, the upper and lower plates through openings provided therein. At this same end of the cartridge, the end of the arms of the U-shaped frame which are remote from the bight portion are supported in spaced relation by a pin and this pin also pivotally supports one end of a spring actuator. At the other end of the cartridge, the end of the arms of the U-shaped frame which are remote from the bight portion are held in spaced relation by another pin which pivotally supports a gear segment. The opposite arcuate ends of this gear segment are pivotally connected to the other end of the spring actuator and the piston rod of the hydraulic door check mechanism. To accommodate a spring actuator having an outside dimension greater than the distance between the outer sides of the plates, the margins of the arms, or plates, of the frame are recessed between the ends of the spring actuator.

To install the cartridge, the end of the cartridge having the gear segment is inserted through the opening in the top of the casing in a direction toward the drive spindle. As the cartridge is positioned horizontally in the casing, a threaded pin or bolt is inserted through aligned openings provided in the arms of the cartridge, adjacent to the gear segment, and is threaded into a socket in the bottom wall of the housing to pivotally mount that end of the cartridge. The cartridge is then rotated relative to the sides of the casing until its gear segment is brought into driving engagement with the spindles gear segment. The other end of the cartridge is then secured into position by a screw that extends through openings in the arms of the frame and is threaded into a threaded bore in the bottom wall of the housing. Alternately, positioning may be effected by an adjustable screw carried by the bight portion of the frame of the cartridge and reacting against a side wall of the housing.

The removable cartridge is designed to optionally include a door hold-open device. The door hold-open device uses a springbiased, pivotally-mounted blocking member whose free end includes a blocking notch. When the gear segment of the cartridge is rotated through approximately ninety-degree angle due to the door being opened, a roller carried by the gear segment falls into this blocking notch to prevent the gear segment from reversing its direction and consequently, the door is held open. The door hold-open device also has a two-position selector member to move the latching member to either a h0ld-open or non hold-open position.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention, reference may be had to the accompanying drawings in which:

FIG. 1 is a top plan view of a new and improved door control unit constructed in accordance with the features of the present invention with the top cover partially broken away;

FIG. 2 is a vertical sectional view taken substantially along the line 22 of FIG. 1;

FIG. 3 is a top plan view, on a slightly larger scale, of a removable cartridge which is adapted to be inserted in the door control unit of FIG. 1;

FIG. 4 is a front elevational view of FIG. 3, looking in the direction of the line 44 of FIG. 3;

FIG. 5 is an alternative embodiment that is constructed in accordance with the principles of this invention and includes a door hold-open mechanism;

FIG. 6 is a vertical sectional view taken substantially along the line 6-6 of FIG. 5; and

FIG. 7 is a vertical sectional view taken substantially along the line 77 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, there is shown a door control unit which is generally designated by the reference numeral 10. In order to keep the overall vertical dimensions of the door control unit 10 as small as possible, a single housing 12 serves as the usual cement case and also as the housing for the door control unit 10. Rotatably mounted at one end of the housing 12 in its upper and lower walls 11 and 13 is a drive spindle 14 and its associated gear segment 16. A cover for the housing may be secured by screws 114 to the housing 12. Extending between the drive spindle 14 and the other end of the housing 12 is a cartridge 18, which contains the remaining operating components of the door control unit 10.

As best illustrated in FIG. 3, cartridge 18 is a selfcontained unit which supports a hydraulic door check mechanism, indicated generally by the numeral 20, a gear segment 22 and a spring actuator 24, which actuator connects with the prior two structures. As will be described in complete detail hereinafter the cartridge unit 18 can be installed and removed for repairs or replacement without the necessity of disengaging the linkage that couples the drive spindle to the door as has been necessary in previous door control units. It is only necessary to move the door to an open position, and to remove the cover 30, in order to be able to remove the cartridge from the housing. There is no need to take the door off its support.

Assuming, for example, that the housing 12 of the door control unit 10 is installed in a floor beneath, and in alignment with, the door when it is in its closed position, an installer of the cartridge will remove the exposed screws 114 and the cover 30. With the door in open position he can then install the cartridge 18 in the housing 12 by inserting the end 26 of the cartridge 18 which is adjacent to the gear segment 22 through the open top of housing 12 in the direction of the drive spindle 14. As the installer positions the cartridge horizontally in the casing 12, he pivotally mounts end 26 in casing 12 by inserting a pin or bolt 27, which is threaded at its lower end 27a (see FIG. 6) through opening 23 in casing 12 and aligned openings 110 in cartridge 18 and into a threaded socket 27b (FIG. 6) in bottom wall 13 of the housing. The other end 29 of the cartridge 18 is then rotated about bolt 27 until teeth 28 of gear segment 22 engage with teeth 17 of gear segment 16. To complete the installation, the other end 29 of cartridge 18 is secured in that position in the housing 12 by a screw 112 and the cover 30 is placed over the top opening of housing 12 and is secured thereto by screws 114. 0 An alternate way of securing the cartridge 18 in housing 12 so that gear segment 22 is in driving relation to gear segment 16 is to use an adjusting screw 120 (FIG. 3) whlch may be threaded in and out of a threaded aperture 122 in the bight portion 38 of cartridge 18. As shown in FIG. 1, in dotted line, screw 120 can be substituted for screw 112 and can position the gear segments in driving relation by being threaded to a position Where the head of screw 120 engages side wall 82 of the housing. If wear occurs, screw 120 can be used to adjust the cartridges position to compensate for such wear.

As best shown in FIGS. 3 and 4, the frame 32 for the cartridge 18 consists of two spaced plates 34 and 36 that are interconnected by a bight portion 38 to form a U- shaped cross section. If desired, the frame may be made of two parts, welded together at the bight portion, for example. The hydraulic door check mechanism 20 is mounted between the plates 34 and 36 at the right end (as viewed in FIGS. 3 and 4) of the cartridge 18 adjacent to the bight portion 38. To keep the overall vertical dimensions of the cartridge 18 as small as possible, the upper and lower portions 40 and 42 of the casing 41 of door check mechanism 20 protrude above and below the plates 34 and 36, respectively, through aligned openings 43 that are cut into the plates 34 and 36, as best seen in FIG. 3. By permitting the casing 41 of the door check mechanism to project through openings in these two plates the overall vertical dimension of the cartridge 18 is reduced by a factor equal to the sum of the thicknesses of plates 34 and 36. The hydraulic door check mechanism 20 is shown in outline form only, since its construction and operation are not a part of the invention described herein. For details of the description and operation of a suitable hydraulic door check mechanism, such a mechanism 20, reference may be had to US. application of Richard E. DHooge, Ser. No. 832,900, filed June 13, 1969, which has the same assignee as this application. The hydraulic door check mechanism disclosed in the above-mentioned patent application has a single cylinder in this casing (which casing is herein shown at 41) with a double acting piston (not shown) to provide reliable door control in both directions of movement of the door. The double-acting piston has a piston rod, here shown at 45 in FIG. 3 of the drawings. The oil reservoir for the door check mechanism 20 is disposed between the plates 34 and 36 in the area indicated by dotted lines 44 in FIG. 3. Of course, other hydraulic door check mechanisms could be mounted in the cartridge 18.

In order to maintain in spaced relation the ends of the arms formed by plates 34 and 36 which are remote from the bight portion 38, pins 46 and 52 are used at the opposite ends 29 and 26, respectively, of cartridge 18. The pin 46 also serves as a pivot connection for one end of spring actuator 24. The pin 46 is passed through aligned openings provided in the plates 34 and 36 and through a carrier 48 which has a telescoping connection with the tubular portion 49 of the spring actuator 24. The split ends 50 of pin 46 are spread outwardly in a conventional manner to lock pin 46 in place. Similarly, a pin 52 is inserted through aligned openings in plates 34 and 36 and the axial opening of gear segment 22 which is disposed between the spaced plates. The other end 54 of spring actuator 24 which is connected with the tubular portion 49 is coupled to one of the ends 56 of gear segment 22 by a pivot pin 58. A spring 72 encircles the portions 48 and 49 of spring actuator 24..

A link 60 interconnects the other end 62 of gear segment 22 to piston rod 45 of hydraulic door check mechanism 20. Link 60 is pivotally connected to piston rod 45 and to the end 62 of gear segment 22 by pivot pins 64 and 68, respectively.

To guide the movements of the piston rod 45 of the double acting piston in a straight path parallel to the pis ton cylinder, slots 66 and 70 are formed in both plates 34 and 36. The pins 64 and 68 extend upwardly and downwardly through slots 66 and 70, respectively, and are approximately the width of the slots. Thus, the left end of link 60 follows exactly the arcuate movements of gear segment 22 and the right end of link 60 moves in a straight path as pin 64 rides in slots 66.

To keep the overall vertical dimension of the cartridge 18 as small as possible the frame 32 is specifically designed to permit the outside dimension of spring 72 of spring actuator 24 to exceed the confines of the frame, for if the spring 72 were disposed between the base plates 34 and 36, the overall vertical height of the cartridge 18 would be increased by approximately the thickness of the plates 34 and 36. As shown in FIG. 3, the margin 74 of plates 34 and 36 is recessed betweent hep ivot pins 46 and 58 of spring actuator 24, the deepest portion of the recess being at point 76, which coincides with the extreme rotational position of gear segment 22 as the door is swung to the fully open position.

The housing 12 of the door control unit 10 has a generally rectangular shaped bottom wall 13 with integrally formed vertically extending sidewalls 82. To maintain the overall vertical dimension of the door control unit 10 as small as possible, the vertical height of sidewalls 82 is only slightly larger than the overall height of cartridge 18. At the left side of the housing 12 (as viewed in FIGS. 1 and 2) there is integrally formed with the top edge of the sidewalls 82 a top portion 11 which extends across the width of the casing 12 and along its length for a short distance. The top wall portion 11 serves as a support for the upper portion of spindle 14, and also for holding the upper end of bolt or pin 27 which pivotally mounts the forward end 26 of cartridge 18 in the casing 12. Since the largest vertical dimension of the cartridge 18 is between its ends, because of spring 72 and casing 41, the bottom wall 13 has two raised portions 88 and 90 extending across its width to support the ends of cartridge 18 in elevation a short distance above the surface of bottom wall 13. The bottom wall between the raised portions 88 and 90 is also somewhat recessed to make easier the insertion of the cartridge 18 in housing 10.

The sidewalls 82 of casing 12 have an upturned flange 92 that extends around three sides of cover plate 30 and together with a flange 94 integrally formed on the inside surface of top wall portion 11 define a thin rectangular shaped projection to engage the margins of cover plate 30. To seal the door control unit 10 from dirt, water and the like, a shorter flange 96 is integrally formed around the three sides of the sidewall 82 inside flange 92 and, together with the innermost portion 98 of flange 94 define a second rectangular shaped edge. Sealing is provided by a strip of rubber or plastic 97 (FIG. 2) that overlaps the upper edges of flanges 96 and portion 98 of flange 94.

The spindle 14, having an upper exposed shank portion [102 which is non-circular in cross section, is supported for rotation in an upper bearing 104, which is connected with the top wall portion 11 of housing 12, and in a lower bearing 106 which is carried by the bottom wall 13 in raised portion 88. Secured to the lower end of the spindle 14 is gear segment 16 having teeth 17 (shown in dotted lines) which mate with teeth 28 of gear segment 22. Bearing 104 is threadedly removable from housing 12 thereby permitting spindle 14 and gear segment 16 to be removed.

From the above description of the door control unit 10, it should be readily apparent that the installation and removal of cartridge 18 is a very quick and simple procedure. To install the cartridge 18 in the casing 12, the end 26 of cartridge 18 is inserted into the top opening of casing 12 and fitted between the top wall portion 11 and the raised portion 88 of bottom wall 13. Simultaneously the other end 29 of the cartridge 27 is swung downwardly into the casing 12 and permitted to rest on raised portion 90. The front end 26 is then pivotally connected to the casing 12 by a bolt or pin 27 which is inserted through an opening 23 provided in top wall portion 11, passed through the openings 110 of cartridge 18 and screwed into a threaded socket 27b (FIG. 6) in raised portion 88. Thereafter, the other end 29 of cartridge 18 is swung clockwise (as viewed in FIG. 1) through a short distance until gear teeth 28 of gear segment 22 drivingly engage gear teeth =17 of gear segment 16. To hold the cartridge in this position, the screw 112 at the end 29 of cartridge 18 is then fastened in a threaded bore 113 that is formed in raised portion 90 of the bottom wall 30. To complete the installation, the cover plate 30 is placed over the top opening in casing 12 and screws 114 are passed through openings in the cover and are screwed into the corresponding threaded bores 116 formed around the periphery of bottom wall 30. To remove the cartridge 18 from the housing 12 the above-mentioned steps are reversed.

There is illustrated in FIGS. -6 an alternative embodiment of the cartridge of this invention wherein a novel door hold-open mechanism 1'30 has been added. The cartridge is designed so that the hold-open mechanism 130 can be made an optional feature of the door closure unit 10. Consequently, the arrangement of parts of the cartridge 18- depicted in FIGS. 3 and 4 is substan tially the same as the arrangement shown in FIGS. 5 and 6 and the parts will be designated with the same reference numerals where the parts are the same. One structural difference of FIGS. 5, 6 and 7 resides in substituting for one link 60 which is disposed between plates B4 and 36 of cartridge 18, two links 60 which are disposed on the outer sides of plates 34 and 36. Pivot pin 64 which connects piston rod 45 with the links 60, passes through slots 66 in plates 34 and 36. Similarly, pivot pin 68 which connects the links 60 with gear segment 22 passes through curved slots 70 in plates 34 and 36. In this way space is provided between plates 34 and 36 for the door hold-open mechanism 130. The normal operation of the door closure unit 10 is that when the door is opened the gear segment 16 coupled to the drive spindle 114 is rotated in a clockwise direction (FIG. 5) and gear segment 16 drives gear segment 22 counterclockwise. Upon releasing the door, the compressed spring 72 of spring actuator 24 drives the gear segment 22 clockwise until the door is closed. The hold-open mechanism 130 cooperates with the pivot pin 68 on the end 62 of gear segment 22 in such a manner that, when the door is open through an angle of approximately a blocking member 134 of the hold-open mechanism engages and blocks an engagement member, in the form of a hard steel roller 132 on pin 68, to prevent the counter-rotation of thegear segment 22 upon the release of the door. The blocking member 134 is pivotally connected between the spaced plates 34 and 36 of the cartridge 18 by a pivot pin 136. The free end 138 of the blocking member 134, which is thinner than its pivoted end 139, is positioned such that the roller 132 rides along the longitudinal side 140 facing the roller 132, when the hold-open mechanism has been set in its operative position as shown in FIG. 5. The free end 138 is notched, as at 142, at the corner closest to the roller 132, the angle encompassed by the notch being about 120 (see FIG. 5). To assist the roller 13-2 in riding into and out of notch 142, the corner 144 which joins the side 140 to the adjacent inclined surface i143 of notch 142 is rounded.

To bias the free end 138 of the blocking member 134 against the roller 132 for all positions of the gear segment 22, a biasing mechanism 145 is provided having one end coupled to the middle section of blocking member 134 by a pivot pin 148 and its other end secured to the middle portion of a two-position selector member 150. The biasing mechanism 145 comprises a housing 146, for a compression spring 147, and a threaded bolt 149 which is apertured at its bifurcated end 149a to receive the pivot pin 148 which also passes through latching member 134. One end of spring 147 engages an inturned flange 146a of housing 146 and the other end of spring 147 engages a washer and nut, indicated at 1491) and 14%, respectively. The shank of bolt 149 passes through the space at the core of spring 147 and inturned flange 146a 'of housing 146. Housing 146 at is other end passes through an aperture in and is connected with the selector structure '150 which is used to place the hold open mechanism in either its operative position (as shown) or in its inoperative position.

The two-position selector member 150 consists of two spaced plates 152 and 154 (partially shown in- FIG. 6) which are joined by a bight portion 153 at their right hand portions (FIG. 5) and are pivotally mounted by pivot pin 156 above and below the cartridge plates 34 and 36, respectively. Free ends 158 and 159 of plates 152 and 15 4, respectively, are selectively movable between two positions by a cam member 160. The cam member 160 consists of a pin member 162 having a slot in its upper exposed end 164 and two cam discs 166 and 168, respectively, which are fixed to the pin 162 and adapted to fit within the square-shaped openings 170 and 172 provided, respectively, in free ends 158 and 159 of plates 152 and 154. The upper end 164 of pin 1'62 fits into an aperture 161 formed in the cover 30 of the door closure unit 10 to enable the user to selectively position the cam member 160 in either the hold-open or non hold-open position. The hold-open position is depicted in solid lines in the FIG. drawing and the non hold-open position is depicted in dotted lines in the FIG. 5 drawing.

As 'viewed in FIG. 5, the door has been swung to the fully open position and roller 132, on pin 68 of gear segment 22, has rolled along the edge 140 of the blocking member 134 until the notch 142 came to the roller, whereupon the blocking member 134 was pulled toward the roller by the biasing mechanism 145 into the position shown in FIG. 5. With the blocking member 134 so disposed, when the door is released it cannot swing to closed position under the urging of the spring actuator 24, the spring 72 of which was compressed during the door opening movement. When it is desired to close the door, it is pulled, whereupon the roller, acting on the inclined surface 143 of notch 142, causes the blocking member 134 to be cammed out of the way. The door will then be closed by the spring actuator causing gear segment 22 to rotate in a clockwise direction and to cause the gear segment 16 and spindle 14 to rotate in a counterclockwise direction.

To assure that gear segment 22 of cartridge 18 will be appropriately associated with gear segment 16' of door spindle 14 when the door is in open position and the cartridge is ready to be inserted into the housing 12, the gear segment 22 will first be rotated counterclockwise from its FIG. 3 position to a position corresponding to the open position of the door. This will result in compression of the spring actuator 24. So that the spring actuator will not be able to return the gear segment to its FIG. 3 position before the cartridge 18 is inserted into the housing 12 and correctly aligned with gear segment 16, retaining means in the form of a pin 21 having a finger grip end 23 (shown in dotdash lines in FIGS. 4 and 5) is insertable through a pair of aligned holes, such as hole 25, in the two spaced plates 34 and 36 of cartridge 18. The edge of gear segment 22 will abut the pin 21. After the cartridge is installed and aligned properly, pin 21 is pulled out of the holes. The pin 21 is also useful when removing the cartridge 18 from housing 12.

The door control unit of the present invention represents a significant advance in the door closer art, for it permits the operating parts of the door closer unit which periodically need repair or replacement to be removed as a unit from the housing without the necessity of disconnecting the door from the drive spindle. Also the unit is much shallower than prior door control units, thereby permitting its installation in locations where prior units could not be placed for lack of space.

I claim:

1. An improved door control unit comprising, in combination, an open-top housing which serves as a cement case and a cartridge removable therefrom as a unit, said housing including a top wall portion across one side of the housing, a spindle rotatably supported in said top wall portion of the housing and adapted for assembly with a door, and a driving member supported on the spindle beneath said top wall portion and rotatable with the spindle in response to opening and closing of a door assembled with the spindle, said cartridge comprising a frame on which is supported a hydraulic door checking mechanism having a piston rod and a driven member for operating said piston rod, said dri-ven member being supported on said cartridge frame adjacent one end thereof, said cartridge including its door checking mechanism and driven member being insertable as a unit through the open top of the housing in order to dispose said driven member below said top wall portion of the housing and in operative relationship with the driving member of the spindle without removing the door from the spindle, and releasable means which locate said cartridge when in the housing so as to hold its driven member in said operativeassociation with the driving member of the housing in order that the driven member actuates the hydraulic door checking mechanism when driven by the driving member in opening and closing a door mounted on the spindle.

2. The unit of claim 1 together with a cover removably enclosing said open top of the housing.

3. The unit of claim 1 wherein the means for locating said cartridge in the housing include a member secured to the housing and pivotally connecting the cartridge within the housing.

4. The unit of claim 3 together with means for adjusting the position of the pivotally supported cartridge and its driven member relative to said driving member.

5. The unit of claim 1 wherein the housing has a bottom wall providing, at one end, a cartridge supporting portion and having a recessed area adjacent to said supporting portion.

6. The unit of claim 1 wherein the hydraulic door checking mechanism comprises a single cylinder with a double acting piston having its piston rod extending out of the cylinder and being operatively connected with said driven member, and wherein the door checking mechanism has a self-contained hydraulic circuit with a reser- 7. The unit of claim 1 wherein the rotatable driving member of the housing is a gear segment and the cartridge comprises a pair of plates supported in spaced generally parallel relation and the driven member is a gear segment supported for rotation between said plates.

8. The unit of claim 1 wherein the cartridge comprises a pair of plates supported in spaced generally parallel relation, at least one of said plates having an opening in which opening the casing of the hydraulic door checking mechanism is disposed and from which the casing partially protrudes.

9. The unit of claim 1 together with a spring actuator acting between the cartridge and the driven member and wherein the piston rod of the hydraulic door checking mechanism is pivotally connected with the driven member.

10. The unit of claim 9 wherein said cartridge further comprises a door hold-open mechanism which operatively engages and blocks said driven member from counterrotation upon said driven member being rotated through a predetermined angle in a door opening direction.

'11. An improved door control unit comprising a housing which serves as a cement case, a spindle supported by the housing for rotation, a driving member in the housing rotatable when the spindle rotates, and a cartridge insertable into and removable from the housing without removing the door from the spindle, said cartridge comprising a hydraulic door checking mechanism having a casing and a piston rod, and a driven member, said driven member being adapted upon insertion of the cartridge into the housing to be disposed in operative association with said driving member and being adapted, when driven, to actuate the hydraulic door checking mechanism, said cartridge further including a spring actuator acting between the cartridge and the driven member and wherein the piston rod of the hydraulic door checking member is pivotally connected with the driven member, and a door hold-open mechanism which operatively engages and blocks said driven member from counter-rotation upon said driven member being rotated through a predetermined angle in a door opening direction and further comprising a roller carried by said driven member and with said door holdopen mechanism including a pivotally-connected blocking member having a notch formed at its free end facing said roller and including spring means for biasing said free end against said roller, whereby said roller rides into and is blocked by said notch, whenever said driven member rotates through a predetermined angle, to prevent counterrotation of said driven member.

12. The unit of claim 11 wherein said hold-open mechanism further includes means for selectively moving said free end of said blocking member away from said roller to render said hold-open mechanism inoperative.

13. The unit of claim 7 wherein said cartridge further comprises a door hold-open mechanism which operatively engages and holds said driven member from counterrotation upon said driven member being rotated through a. predetermined angle and which is disposed between said pair of plates and a selector member extending through an aperture in the cover plate for said housing to adapt to selectively place said hold-open mechanism in either an operative or inoperative position, said selector member being operable from the exterior of the housing.

14. The unit of claim 9 wherein the outside dimension of the spring actuator and the thickness of the casing of the hydraulic door checking mechanism exceed the distance between the outer sides of said plates.

15. The unit of claim 14 wherein the spring actuator and the casing of the hydraulic door checking mechanism each protrude approximately equally beyond the outer sides of said plates.

16. The unit of claim 1 wherein the cartridge also comprises a spring actuator connected between the cartridge and the driven member.

17. The unit of claim 16 wherein the cartridge further comprises a frame having a pair of spaced plates maintained in spaced relation at one location by a pin, and wherein the spring actuator is operatively connected by one end with said pin for pivotal movement about said pm.

18. The unit of claim 16 wherein the carriage further comprises a frame having a pair of spaced plates and the driven member is pivotally supported between said plates.

:19. The unit of claim 16 wherein the cartridge further comprises a frame having a pair of spaced plates and the margins of the frame are recessed to at least partially accommodate the spring actuator.

20. The unit of claim 16 wherein the cartridge is pivotally supported adjacent one end in the housing and has means acting between the cartridge and the housing for adjusting the position of the cartridge and the driven member relative to the driving member.

21. For use with a door control unit having a housing which supports a driving member which is responsive to movement of a door assembled therewith, the improvement which comprises a cartridge separable as a unit from a housing and its driving member, said cartridge comprising a frame having a pair of spaced plates between which is supported a driven member, a hydraulic door checking mechanism carried by the frame and having a casing and a piston rod operatively connected with the driven member, a spring actuator acting between said frame and said driven member, said driven member being adapted, upon insertion of the cartridge into the housing, to be disposed in operative association with said driving member, and means for securing the cartridge frame to said housing to locate the driven member in operative association with the driving member of the housing.

22. The cartridge of claim 21 together with means for adjusting the position of the cartridge and said driven member relative to said driving member when the cartridge is inserted in the housing.

23. The cartridge of claim 21 wherein the spaced plates have aligned openings in which openings the casing of the hydraulic door checking mechanism is disposed and from which openings the casing partially protrudes.

24. The cartridge of claim 23 wherein the spring actuator is disposed at least partially in a recessed area of the margins of said plates, and wherein the diameter of the spring actuator and the thickness of the casing of the hydraulic door checking mechanism exceed the distance between the outer sides of said plates.

25. For use with a door control unit having a housing which supports a driving member which is responsive to movement of the door, the improvement which comprises a cartridge comprising a frame having a pair of spaced plates between which is supported a driven member, a hydraulic door checking mechanism carried by the frame and having a casing and a piston rod operatively connected with the driven member, a spring actuator acting between said frame and said driven member, said driven member being adapted, upon insertion of the cartridge into the housing, to be disposed in operative association with said driving member, the cartridge further comprising an engagement member carried by said driven member, and a door hold-open mechanism including a blocking member having one end pivotally mounted between said plates and the other end having a notch formed at a corner in an opposed relation to said engagement member, and spring means for biasing said other end against said roller, whereby said engagement member rides into and is blocked by said notch whenever said driven member is rotated in a door opening direction through a predetermined angle, to prevent counter-rotation of said driven member.

26. The cartridge of claim 25 wherein said door holdopen mechanism further includes a means for selectively moving said other end of said engaging member away from said engagement member to render said hold open mechanism inoperative.

27. The cartridge of claim 25 wherein the notch has an inclined blocking surface for blocking the engagement member but which surface may be cammed out of the way when struck by said engagement member following its further movement in a door opening direction beyond said blocking position and then release of the door.

28. The cartridge of claim 25 wherein the engagement member is a pivot pin carried by the driven member for connecting the driven member to the piston rod of the hydraulic door checking mechanism.

29. The unit of claim 1 wherein the spindle is rotatably supported in the housing by removable bearing means which permits removal of the spindle and the driving member from the housing.

30. The cartridge of claim 21 together with removable means for retaining the driven member in a position corresponding to a door-open position and with the spring actuator in a stressed condition.

References Cited UNITED STATES PATENTS 2,820,243 l/1958 Gibbons 16185 2,933,755 4/1960 Carlson 16-55 2,971,212 2/1961 Voster et a1. 16-55 FOREIGN PATENTS 548,087 6/1956 Belgium l6-55 943,749 12/ 1963 Great Britain 16-62 BOBBY R. GAY, Primary Examiner P. A. ASCHENBRENNER, Assistant Examiner U.S. Cl. X.R. 16--51, 58 

